Bewaard in:
| Hoofdauteurs: | , |
|---|---|
| Formaat: | Preprint |
| Gepubliceerd in: |
2025
|
| Onderwerpen: | |
| Online toegang: | https://arxiv.org/abs/2503.07708 |
| Tags: |
Voeg label toe
Geen labels, Wees de eerste die dit record labelt!
|
| _version_ | 1866910086385893376 |
|---|---|
| author | Gioia, Lei Thorngren, Ryan |
| author_facet | Gioia, Lei Thorngren, Ryan |
| contents | We construct Hamiltonian models on a 3+1d cubic lattice for a single Weyl fermion and for a single Weyl doublet protected by exact (as opposed to emergent) chiral symmetries. In the former, we find a not-on-site, non-compact chiral symmetry which can be viewed as a Hamiltonian analog of the Ginsparg-Wilson symmetry in Euclidean lattice models of Weyl fermions. In the latter, we combine an on-site $U(1)$ symmetry with a not-on-site $U(1)$ symmetry, which together generate the $SU(2)$ flavor symmetry of the doublet at low energies, while in the UV they generate an algebra known in integrability as the Onsager algebra. This latter model is in fact the celebrated magnetic Weyl semimetal which is known to have a chiral anomaly from the action of $U(1)$ and crystalline translation, that gives rise to an anomalous Hall response - however reinterpreted in our language, it has two exact $U(1)$ symmetries that gives rise to the global $SU(2)$ anomaly which protects the gaplessness even when crystalline translations are broken. We also construct an exact symmetry-protected single Dirac cone in 2+1d with the $U(1) \rtimes T$ parity anomaly. Our constructions evade both old and recently-proven no-go theorems by using not-on-siteness in a crucial way, showing our results are sharp. |
| format | Preprint |
| id |
arxiv_https___arxiv_org_abs_2503_07708 |
| institution | arXiv |
| publishDate | 2025 |
| record_format | arxiv |
| spellingShingle | Exact Chiral Symmetries of 3+1D Hamiltonian Lattice Fermions Gioia, Lei Thorngren, Ryan Strongly Correlated Electrons Mesoscale and Nanoscale Physics High Energy Physics - Lattice High Energy Physics - Theory Mathematical Physics We construct Hamiltonian models on a 3+1d cubic lattice for a single Weyl fermion and for a single Weyl doublet protected by exact (as opposed to emergent) chiral symmetries. In the former, we find a not-on-site, non-compact chiral symmetry which can be viewed as a Hamiltonian analog of the Ginsparg-Wilson symmetry in Euclidean lattice models of Weyl fermions. In the latter, we combine an on-site $U(1)$ symmetry with a not-on-site $U(1)$ symmetry, which together generate the $SU(2)$ flavor symmetry of the doublet at low energies, while in the UV they generate an algebra known in integrability as the Onsager algebra. This latter model is in fact the celebrated magnetic Weyl semimetal which is known to have a chiral anomaly from the action of $U(1)$ and crystalline translation, that gives rise to an anomalous Hall response - however reinterpreted in our language, it has two exact $U(1)$ symmetries that gives rise to the global $SU(2)$ anomaly which protects the gaplessness even when crystalline translations are broken. We also construct an exact symmetry-protected single Dirac cone in 2+1d with the $U(1) \rtimes T$ parity anomaly. Our constructions evade both old and recently-proven no-go theorems by using not-on-siteness in a crucial way, showing our results are sharp. |
| title | Exact Chiral Symmetries of 3+1D Hamiltonian Lattice Fermions |
| topic | Strongly Correlated Electrons Mesoscale and Nanoscale Physics High Energy Physics - Lattice High Energy Physics - Theory Mathematical Physics |
| url | https://arxiv.org/abs/2503.07708 |